Helices in Proteins
From Proteopedia
Helical conformations in proteins
This page illustrates the 3 most common helical conformations (among secondary structures) found in proteins.
Each of the three examples below is a decapeptide fragment extracted from an actual protein structure in the PDB. They are shown using the same scale, for a better comparison (as a consequence, zoom in the Jmol applets is disabled).
To re-align the 3 models, either reload this page or click on each of the 3 green 'Reset' links.
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Change rendering:
The alpha helix is by far the most common helix. Note that it is a right-handed helix when formed with the common L-amino acids[1][2][3]. (It is left-handed when formed with D-amino acids[1][2][3].) When viewed from either end, right-handed helices turn clockwise when followed away from you.
See Also
- Basics of Protein Structure
- Alpha helix
- JSmol helix builder
- RIBOZOME - an Alpha Helix Generator
- Alpha helix at Wikipedia.
- 3-10 helix at Wikipedia.
- Pi helix at Wikipedia.
- Secondary structure
- Protein primary, secondary, tertiary and quaternary structure (slides for teaching)
- The same in Spanish: Estructuras primaria, secundaria, terciaria y cuaternaria de las proteínas (en formato de presentación)
References
- ↑ 1.0 1.1 Novotny M, Kleywegt GJ. A survey of left-handed helices in protein structures. J Mol Biol. 2005 Mar 25;347(2):231-41. PMID:15740737 doi:10.1016/j.jmb.2005.01.037
- ↑ 2.0 2.1 Jourdan F, Lazzaroni S, Mendez BL, Lo Cantore P, de Julio M, Amodeo P, Iacobellis NS, Evidente A, Motta A. A left-handed alpha-helix containing both L- and D-amino acids: the solution structure of the antimicrobial lipodepsipeptide tolaasin. Proteins. 2003 Sep 1;52(4):534-43. PMID:12910453 doi:http://dx.doi.org/10.1002/prot.10418
- ↑ 3.0 3.1 Moradi M, Babin V, Roland C, Darden TA, Sagui C. Conformations and free energy landscapes of polyproline peptides. Proc Natl Acad Sci U S A. 2009 Dec 8;106(49):20746-51. Epub 2009 Nov 18. PMID:19923435 doi:10.1073/pnas.0906500106